Nickel-base alloys



United States Patent 3,293,030 NICKEL-BASE ALLOYS 7 Henry C. Child and Adam Dunlop, Rotherham, England,

assignors to The Birmingham Small Arms Company Limited, Birmingham, England, a British company No Drawing. Filed May 9, 1963, Ser. No. 279,301 Claims priority, application Great Britain, May 12, 1962, 18,338/ 62 2 Claims. (Cl. 75-171) This invention relates to nickel base casting alloys useful for the production of highly stressed components ope-rating at elevated temperatures, for example, gas-turbine blades. For such application the alloys used must have good creep rupture strength at the operating temperatures as well as satisfactory oxidation and corrosion resistance.

Nickel-base alloys have 'become well established for such purposes, the desired resistance to oxidation and corrosion being obtained by having a substantial chromium content ranging from 10% to while elevated temperature strength is attained by the addition of strengthening agents such, for example, as aluminium, titanium, tungsten, molybdenum and the like.

We have found that by reducing the chromium content 3,293,030 Patented Dec. 20, 1966 the following more restricted ranges may be used, the proportions being by weight:

' Nickel and impurities, balance.

1 Together 7-1'1 In place of tungsten alone in this more restricted range molybdenum may also be present according to the formula 2 Mo+W=ll-20%.

The following are examples of alloys according to the invention the proportions being by weight percent.

Ni and Creep Rupture C Cr Co B Zr Ti Al W M0 Nb Impurities Hours 15 T.S.I.

at 950 C.

0.1 5 10 05 05 5 4 Bal. 93 0.1 5 10 05 05 4 4 B51. 140 0.1 5 10 05 05 5 4 B51. 108 0. 1 5 10 05 05 5 4 B51. 140 0.1 5 10 .05 05 4 5 B51. 154 0. 1 5 10 05 05 4 4 B51. 194 0.1 5 10 .05 05 4 4 B51. 147 0. 1 5 10 05 05 4 4 B51. 175 0.1 5 10 05 05 4 4 14 5 B51. 72 0.1 5 10 05 05 4 4 8 s Bal. 53 0. 1 9 10 05 05 4 4 s 5 1 B51. 103 0. 1 9 10 05 05 2 5. 5 s 3 1 B51. 138 0. 0s 9 10 0. 025 05 2 5. 5 4 4 1 B51. 128

to below 10%, higher total percentages of hardening The stress for rupture properties of a vacuum induction agents (for example, alummlum, tltanium, tungsten and cast nickel-base alloy according to the invention consisting molybdenum) can be used with sigmficant increase in in percentage -by weight of 0.1% carbon, 5% chromium, creep rupture strength. 10 cobalt, .05% boron, .05% zirconium, 4% titanium,

According to this invention alloys havlng good creep 4% aluminium and 16% tungsten, are as follows: rupture strength and resistance to oxidation and corrosion consist essentially of the following, the proportions being Time, Tempew Stress for by Welghtl hours ture, C. Rupture, tons Percent per sq. mch Carbon ODS-0.5

30 050 20 Chromium 3 10 1,000 13.5 Boron 0001-03 1,030 10.7 Zirconium 0001-03 1150 Titanium 2-7 100 950 15. 7 Aluminium l V ijgg 2:2 Tungsten 11 050 1 Silicon 300 950 12. '1 Manganese 1, 000 s. 6 1 030 .5 Cobalt 04(5) 11050 2.8 Iron 1, 000 950 10.2 N1ob1um 1, 000 5.5 Tantalum Nickel and impurities, balance. 1 Extrapolated.

In place of tungsten alone, molybdenum may also be present according to the formula 2 Mo+W=8-24%. In place of any or all of the ranges mentioned above The impact result on an unnotched Ized specimen of this alloy at 900 C. was 2 6 to 34 ft. lbs.

It has been found that while the molybdenum-containing alloys may have lower creep rupture properties this may be compensated for in use for moving parts such as turbine blades by the lower density of such alloys, In addition the presence of molybdenum tends to increase the impact strength.

Articles made from alloys according to the invention may be aluminized or chromized with a view to improving resistance to oxidation and corrosion in the way that articles from the alloys with higher chromium contents are at present aluminized or chromized.

We claim:

1. A nickel'base alloy having improved creep rupture strength and resistance to oxidation and corrosion at temperatures in the region of 1000 C. consisting essentially of the following, the proportions being by weight:

Nickel and impurities, balance.

2. Nickel base alloys having improved creep strength and resistance to oxidation and corrosion at temperatures in the region of 1000 C. consisting essentially of th following, the proportions being by weight:

Percent Carbon 0.1 Chromium 5.0 Cobalt 10.0 Boron 0.05 Zirconium 0.05 Titanium 4.0-6.0 Aluminum 4.05 .0 Tungsten 11.0-22.0 Nickel and impurities, balance.

References Cited by the Examiner UNITED STATES PATENTS 2,951,757 9/ 1960 Brown 17l 2,975,051 3/ 1961 Wilson et al. 75171 FOREIGN PATENTS 227,261 12/ 1959 Australia. 202,782 4/ 1959 Germany.

783,955 10/ 1957 Great Britain.

HY LAND BIZOT, Primary Examiner.

WINSTON A. DOUGLAS, DAVID L. RECK,

Examiners.

C. M. SCHUTZMAN, R. O. DEAN, Assistant Examiners. 

2. NICKEL BASE ALLOYS HAVING IMPROVED CREEP STRENGTH AND RESISTANCE TO OXIDATION AND CORROSION AT TEMPERATURES IN THE REGION OF 1000* C. CONSISTING ESSENTIALLY OF THE FOLLOWING, THE PROPORTIONS BEING BY WEIGHT: 